Well back in the 90's when I had my 6ft tank with 60 odd giant danios, tons of home breed Cory's, silver sharks and a big fire eel I got sick of cleaning the filter so I got a DIATOM MODEL "XL" FILTER and connected it up to a Spa Pool canister filter similar to the one at this link. http://www.prowze.co.nz/viewProductSing ... uctID=7294
(imagine an oil filter you use in your car, but 70cm high and around 20 cm wide, it can filter a lot of muck and still flow)
So I had this HUGE canister filter which was upstream of the diatom filter and pump. Result = flush once every six months :-) Perfect clear tank. Getting sick on cleaning my Fluval 304 now so considering an updated set up like I used to have..